491920101 has 16 divisors (see below), whose sum is σ = 729432000. Its totient is φ = 327649104.

The previous prime is 491920087. The next prime is 491920141. The reversal of 491920101 is 101029194.

It is not a de Polignac number, because 491920101 - 2¹⁷ = 491789029 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (491920141) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24375 + ... + 39723.

It is an arithmetic number, because the mean of its divisors is an integer number (45589500).

Almost surely, 2^491920101 is an apocalyptic number.

It is an amenable number.

491920101 is a deficient number, since it is larger than the sum of its proper divisors (237511899).

491920101 is a wasteful number, since it uses less digits than its factorization.

491920101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16545 (or 16539 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 491920101 is about 22179.2718771379. The cubic root of 491920101 is about 789.4019406742.

Adding to 491920101 its reverse (101029194), we get a palindrome (592949295).

The spelling of 491920101 in words is "four hundred ninety-one million, nine hundred twenty thousand, one hundred one".